JPH09161122A - Method for discriminating forged magnetic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely discriminate a forged magnetic card by detecting a step formed at the boundary of the magnetic material coating surface and the punched hole blocking object of the magnetic card from the dimension of a noise wave at the time of reading magnetic information by means of a magnetic head. SOLUTION: At the time of inserting the magnetic card 1 into an insertion part 2, a flatter component reading circuit 4 measures the change of the dimension of the noise wave, namely the dimension of an S/N, by the roughness of the surface at the magnetic material coating surface 12 of the magnetic card 1. At this time, in the case of a forged card which improves the residual frequency by blocking the punched hole 13 showing a residual frequency with the punched hole blocking object 14 such as silver paper, a punched piece and rewriting magnetic data through the use of a card writer, as the projecting stepped part 15 is formed at the boundary of the magnetic material coating surface 12 and the punched hole blocking object 14 of the magnetic card 1, the noise wave generated by the roughness of the magnetic material surface is grown and namely an abnormally large flutter component is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for discriminating a modified magnetic card such as a prepaid card or the like, and more particularly, a magnetic card in which punch holes showing a residual number are formed when magnetic information is read by a magnetic head. It is about.

[0002]

2. Description of the Related Art Recently, prepaid cards have been widely used in place of cash such as coins and bills like telephone cards in public telephones and orange cards in railway tickets.

These prepaid cards usually have a magnetic material coated surface formed by coating a magnetic material on the back surface of a card-shaped substrate made of polyethylene terephthalate having a thickness of, for example, about 0.2 to 0.3 mm. Predetermined magnetic information is written, a magnetic concealing layer is formed on the magnetic information, and various patterns are printed on the surface.

Such a prepaid card is forged because the card itself has the character of cash or a cash voucher.
It is easy to be altered.

Further, in the case of a prepaid card, alteration is easier than forgery, the punch hole indicating the remaining number of the used magnetic card is closed with silver paper or a punching piece, and the magnetic data is rewritten using a card writer. It is general that it can be used again by increasing the frequency of use.

[0006]

However, since the prepaid card was introduced on the premise of automation, it is difficult to visually check the card when using it and prevent crimes. Since a modified magnetic card modifies the magnetic information written using a real magnetic card, it is hard to see that it is a modified product in appearance.

[0007] Therefore, in the past, the present situation is to deal with this type of altered magnetic card by taking measures such as abolishing a high number card such as a telephone card or not using a high number card. Therefore, there is no means for easily and surely identifying the altered magnetic card.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and when magnetic information of a modified card is read by a magnetic head, a magnetic material coated surface of the magnetic card and a punch hole are closed. The step formed at the boundary with the object, the magnitude of the noise wave generated by the roughness of the magnetic surface,
That is, the altered card can be easily and surely identified by detecting it from the flutter component.

[0009]

Next, an embodiment of the present invention will be described.

FIG. 1 shows an example of a card control device having a device for discriminating a modified card used when the present invention is carried out, and mainly includes an insertion portion 2 of a magnetic card 1,
It is composed of a magnetic information reading / writing circuit 3, a flutter component reading circuit 4, a control circuit 5, a device operating circuit 6 and the like.

In the insertion portion 2 of the magnetic card 1, the magnetic information written on the magnetic material coated surface 12 formed by coating the magnetic material on the back surface of the base 11 constituting the magnetic card 1 is converted into a current. Or a magnetic head 7 for writing magnetic information on the information recording layer 12 by a loaded current.

Further, the magnetic information reading / writing circuit 3
Reads the information written in the information recording layer 12 of the magnetic card 1 inserted in the inserting section 2 as a current by the magnetic head 7 and the read / write circuit 3 arranged in the inserting section 2, and at the same time, reads the magnetic head 22. A predetermined current is applied to the information recording layer 12 in the magnetic card 1 to write predetermined magnetic information.

Further, the flutter component reading circuit 4 includes, for example, the magnetic card 1 inserted in the insertion portion 2 of the magnetic card 1.
The size of the noise wave generated by the roughness of the surface generated when the magnetic information written on the magnetic material coated surface 12 is read by the magnetic head 7, that is, the size of the S / N ratio is measured and exceeds the normal size. When the S / N ratio is detected, an OFF signal is sent to the control circuit 5.

Furthermore, the equipment operating circuit 6 is the control circuit 5
The device operating circuit 6 is operated based on the signal read by the magnetic information reading / writing circuit 3 sent via the device to turn on / off the device 8 such as a telephone.

In the card controller constructed as described above, when the magnetic card 1 is inserted into the insertion section 2, the magnetic head 7 converts the magnetic information written in the magnetic card 1 into an electric current, and a magnetic information reading / writing circuit. 3 is read, and an ON signal is sent to the device operating circuit 6 via the control circuit 5 to turn ON the device 8.

At the same time, the flutter component reading circuit 4 changes the magnitude of the noise wave caused by the surface roughness of the magnetic material coated surface 12 of the magnetic card 1, that is, the magnitude of the S / N ratio.
Measured by

At this time, the used magnetic card 1 is used to close the punch holes 13 indicating the residual number formed when the magnetic information is read by the magnetic head with the punch hole closing member 14 such as silver paper or punched pieces. In the case of a modified card in which the magnetic data is rewritten using a card writer to increase the frequency of use, a convex step portion 15 is formed at the boundary between the magnetic material application surface 12 of the magnetic card 1 and the punch hole blocker 14. Since it is formed, the noise wave generated by the roughness of the surface of the magnetic material becomes large, that is, an abnormally large flutter component is detected.

Therefore, when this large flutter component is detected, the flutter component reading circuit 4 to the control circuit 5
To the device operating circuit 6 to prevent the start of the operation of the device 8 or to stop the device 8 if it is operating, and further activate the alarm device 9 if necessary. .

As described above, according to the embodiment of the present invention, the altered magnetic card 4 can be discriminated extremely easily and reliably.

In this embodiment, the case where the convex step 15 is formed at the boundary between the magnetic material application surface 12 of the magnetic card 1 and the punch hole blocker 14 is shown. Even when a convex step is formed at the boundary between the surface 12 and the punch hole blocker 14, it is needless to say that the magnetic card can be easily identified in the same manner.

[0021]

According to the present invention having the above construction, the altered magnetic card can be discriminated very easily and surely, and damage caused by illegal use can be prevented, so that an extremely great economic effect can be obtained. It is a thing.

Further, since the present invention utilizes the flutter component generated at the time of reading, there is no need for specially expensive equipment or equipment for implementation, and the detection accuracy is high, so that an extremely sophisticated modified card can be used. It can be distinguished.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing an example of a card control device having a modified card discrimination device for carrying out the present invention.

[Explanation of symbols]

 1 Magnetic Card 7 Magnetic Head 12 Magnetic Material Application Surface 13 Punch Hole 14 Punch Hole Blocker 15 Step

Claims (1)

[Claims] 1. A method for discriminating a modified magnetic card in which a punch hole indicating a residual frequency is closed and magnetic information is written again on a magnetic material coated surface, wherein the magnetic card is used when the magnetic information is read by a magnetic head. The modified magnetic card is characterized by detecting the step formed at the boundary between the magnetic material application surface and the punch hole blocker from the magnitude of the noise wave generated by the roughness of the magnetic material surface. How to identify a modified magnetic card